Humanized anti-IL-20 antibody and uses thereof

ABSTRACT

The present disclosure provides humanized antibodies specific to human interleukin 20 (IL-20) and uses thereof in treating diseases associated with the IL-20 signaling pathway, e.g., osteoporosis, inflammatory disease (e.g., rheumatoid arthritis), cancer, stroke, and renal failure.

BACKGROUND OF THE INVENTION

Interleukin 20 (IL-20), a pleiotropic inflammatory cytokine, is a member of the IL-10 family, which includes IL-10, IL-19, IL-20, IL-22, IL-24, and IL-26. IL-20 is expressed in monocytes, epithelial cells, and endothelial cells. It acts on multiple types of cells via activating a heterodimer receptor complex of either IL-20R1/IL-20R2 or IL-22R1/IL-20R2. IL-20 has been found to be involved in various diseases, such as psoriasis, rheumatoid arthritis, atherosclerosis, ischemic stroke, osteoporosis, and renal failure. Certain anti-IL-20 antibodies have been reported to possess therapeutic effects in treating IL-20 associated diseases, e.g., osteoporosis and rheumatoid arthritis. U.S. Pat. Nos. 7,435,800, 7,611,705, 7,786,274, 7,837,994, 8,012,478; and US Patent Publications 20110305699 and 20090048432.

Monoclonal antibodies derived from non-human species are routinely used in biochemistry, molecular biology, and medical research. In addition, they are attractive therapeutic agents because of their high target specificity and effector functionality. However, one problem associated with the use of non-human antibodies as therapeutic agents is their immunogenicity, which substantially reduces the in vivo effectiveness of such antibodies. One approach to reduce immunogenicity is humanization, i.e., modifying non-human antibodies to increase their similarity to naturally-occurring human antibodies.

SUMMARY OF THE INVENTION

The present disclosure is based on the development of two humanized anti-IL-20 antibodies, which exhibited unexpectedly high affinity to IL-20 (i.e., K_(d)<3.6×10⁻⁹) and therapeutic effects in treating IL-20-associated diseases, e.g., osteoporosis. Accordingly, one aspect of the present disclosure features a humanized antibody that binds IL-20, particularly human IL-20. This antibody comprises a heavy chain variable region (V_(H)), which comprises an amino acid sequence at least 90% (e.g., 95%, 96%, 97%, 98%, or 99%) identical to SEQ ID NO:1 or SEQ ID NO:3, and a light chain variable region (V_(L)), which comprises an amino acid sequence at least 90% (e.g., 95%, 96%, 97%, 98%, or 99%) identical to SEQ ID NO:5 or SEQ ID NO:7. In one example, the humanized anti-IL-20 antibody comprises a V_(H) chain that comprises SEQ ID NO:1 or SEQ ID NO:3 and a V_(L) chain that comprises SEQ ID NO:5, SEQ ID NO:7, or SEQ ID NO:15.

The humanized anti-IL-20 antibody described above can be a full-length antibody (e.g., an IgG molecule), an antigen-binding fragment thereof (e.g., Fab), or a single-chain antibody.

In another aspect, the present disclosure provides an isolated nucleic acid comprising a nucleotide sequence encoding (i) a V_(H) chain, which comprises an amino acid sequence at least 90% (e.g., 95%, 96%, 97%, 98%, or 99%) identical to SEQ ID NO:1 or SEQ ID NO:3, (ii) a V_(L) chain, which comprises an amino acid sequence at least 90% (e.g., 95%, 96%, 97%, 98%, or 99%) identical to SEQ ID NO:5 or SEQ ID NO:7, or (iii) both. In one example, the nucleic acid comprises (i) a nucleotide sequence of SEQ ID NO:2 or SEQ ID NO:4, (ii) a nucleotide sequence of SEQ ID NO:6 or SEQ ID NO:8, or (iii) both. Also described herein are vectors, which comprise the just-described nucleic acids, and host cells which comprise such vectors. In one example, the vectors are expression vectors and the nucleic acids coding for the V_(H) and/or V_(L) chains are in operable linkage to a suitable promoter. Each of the V_(H) and V_(L) coding sequences can be in operably linkage with an individual promoter. Alternatively, both of the V_(H) and V_(L) genes can be under the control of a common promoter.

In yet another aspect, the present disclosure provides methods for treating diseases associated with an IL-20-mediated signaling pathway, comprising administering to a patient in need thereof an effective amount of the humanized anti-IL-20 antibody described herein, either the antibody per se, or a plasmid(s) for expressing such. Diseases associated with the IL-20 mediated signaling pathway include, but are not limited to osteoporosis, rheumatoid arthritis, cancer, stroke, or renal failure. In one example, the disease is osteoporosis, which can be caused by an inflammatory disease (e.g., rheumatoid arthritis), estrogen deficiency (e.g., menopause), androgen deficiency (e.g., andropause), or cancer-induced osteolysis. In another example, the disease is cancer, such as breast cancer, prostate cancer, colon cancer, lung cancer, renal cell carcinoma, giant cell tumor of bone, oral cancer, esophagus cancer, or multiple myeloma.

Also within the scope of this disclosure are (i) a pharmaceutical composition comprising the humanized anti-IL-20 antibody described herein or a nucleic acid encoding the V_(H) chain of the antibody, the V_(L) chain of the antibody, or both, and a pharmaceutically acceptable carrier; (ii) the just-noted pharmaceutical composition for use in treating a disease associated with an IL-20-mediated signaling pathway, such as those described above, and (iii) the use of the humanized anti-IL-20 antibody or its encoding nucleic acid(s)/vectors in the manufacture of a medicament for the treatment of any of the above described diseases.

The details of one or more embodiments of the invention are set forth in the description below. Other features or advantages of the present invention will be apparent from the following drawings and detailed description of several embodiments, and also from the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are first described.

FIG. 1 is a chart showing the inhibitory effects of a humanized anti-IL-20 antibody on osteoclast differentiation, as compared with the effects of the parent mouse monoclonal antibody mAb 7E and a chimeric antibody derived therefrom. Bone marrow-derived hematopoetic stem cells were cultured with MCSF and RANKL to drive osteoclast differentiation. Addition of an anti-IL-20 antibody as noted above to the culture at a concentration of 500 ng/ml inhibited 50% of osteoclast differentiation.

BRIEF DESCRIPTION OF THE SEQUENCES

SEQ ID NO:1 is the amino acid sequence of the precursor V_(H) chain variable region of exemplary humanized anti-IL-20 antibodies HL1 and HL2.

SEQ ID NO:2 is the nucleotide sequence encoding the amino acid sequence of SEQ ID NO:1.

SEQ ID NO:3 is the amino acid sequence of the mature V_(H) chain variable region (which lacks the signal peptide) of the exemplary humanized anti-IL-20 antibodies HL1 and HL2.

SEQ ID NO:4 is the nucleotide sequence encoding the amino acid sequence of SEQ ID NO:3.

SEQ ID NO:5 is the amino acid sequence of the precursor V_(L) chain variable region of exemplary humanized anti-IL-20 antibody HL2.

SEQ ID NO:6 is the nucleotide sequence encoding the amino acid sequence of SEQ ID NO:5.

SEQ ID NO:7 is the amino acid sequence of the mature V_(L) chain variable region (which lacks the signal peptide) of exemplary humanized anti-IL-20 antibody HL2.

SEQ ID NO:8 is the nucleotide sequence encoding the amino acid sequence of SEQ ID NO:7.

SEQ ID NO:9 is the amino acid sequence of the precursor V_(H) chain variable region of monoclonal antibody 7E.

SEQ ID NO:10 is the amino acid sequence of the precursor V_(L) chain variable region of monoclonal antibody 7E.

SEQ ID NO:11 is the amino acid sequence of the mature V_(H) chain variable region (which lacks the signal peptide) of monoclonal antibody 7E.

SEQ ID NO:12 is the amino acid sequence of human germline antibody V_(H) segment J606.4.82.

SEQ ID NO:13 is the amino acid sequence of the framework regions in human antibody L06102 V_(H) chain (mature form).

SEQ ID NO:14 is the amino acid sequence of the mature V_(L) chain variable region (which lacks the signal peptide) of monoclonal antibody 7E.

SEQ ID NO:15 is the amino acid sequence of the mature V_(L) chain variable region (which lacks the signal peptide) of exemplary humanized anti-IL-20 antibody HL1.

SEQ ID NO:16 is the amino acid sequence of human germline antibody bd2 V_(L) segment.

SEQ ID NO:17 is the amino acid sequence of the framework regions in human antibody BG758592 V_(L) chain (mature form).

DETAILED DESCRIPTION OF THE INVENTION

Described herein are humanized anti-IL-20 antibodies and their uses in treating diseases associated with an IL-20-mediated signaling pathway.

Humanized Anti-IL-20 Antibodies

The humanized anti-IL-20 antibodies described herein were designed based on a parent mouse monoclonal antibody 7E, which is described in U.S. Pat. Nos. 7,435,800 and 7,786,274, and also in Example 1 below.

A “humanized antibody” can be an antibody derived from modifying a non-human antibody to replace certain antibody fragments (e.g., framework regions) with those from a human antibody so as to reduce immunogenicity in humans. The humanized antibody described herein can be in any antibody form. In some embodiments, they are intact immunoglobulin molecules (full-length antibodies), including IgG, IgA, IgD, IgE, and IgM. In other embodiments, the humanized antibodies are antigen binding fragments thereof, e.g., Fab, F(ab′)₂, and Fv. In some instances, they also can be single-chain antibodies or bi-specific antibodies.

Humanized antibodies can be designed as follows. First, the variable regions of V_(H) and V_(L) of a parent non-human antibody are subjected to three-dimensional molecular modeling analysis following methods known in the art. See, e.g., Queen et al., Proc. Natl. Acad. Sci. USA, 86:10029-10033 (1989). Next, framework amino acid residues predicted to be important for the formation of the correct CDR structures are identified using the same molecular modeling analysis. In parallel, human V_(H) and V_(L) chains having amino acid sequences that are homologous to those of the parent non-human antibody are identified from any antibody gene database using the parent V_(H) and V_(L) sequences as search queries. Human V_(H) and V_(L) acceptor genes are then selected.

The CDR regions within the selected human acceptor genes can be replaced with the CDR regions from the parent non-human antibody or functional variants thereof. When necessary, residues within the framework regions of the parent chain that are predicted to be important in interacting with the CDR regions (see above description) can be used to substitute for the corresponding residues in the human acceptor genes.

Provided below is an example of the humanized anti-IL-20 antibodies described herein:

Amino Acid Sequence and Encoding Nucleotide Sequence of the V_(H) Chain of Humanized Anti-IL-20 Antibodies HL1 and HL2:

The underlined region refers to the signal peptide and the boldfaced/italic regions are the CDRs. SEQ ID NOs: 3 and 4 represent the mature V_(H) amino acid sequence (lacking the signal peptide) and its encoding nucleotide sequence, respectively.

Amino Acid Sequence and Encoding Nucleotide Sequence of the V_(L), Chain (VL2) of a Humanized Anti-IL-20 Antibody HL2:

The underlined region refers to the signal peptide and the boldfaced/italic regions are the CDRs. SEQ ID NOs: 7 and 8 represent the mature V_(L) amino acid sequence (lacking the signal peptide) and its encoding nucleotide sequence, respectively.

Also described herein are functional variants of the above disclosed exemplary humanized anti-IL-20 antibodies HL1 and HL2. Such functional variants can comprise a V_(H) chain that comprises an amino acid sequence at least 85% (e.g., 90%, 92%, 94%, 95%, 96%, 97%, 98%, or 99%) identical to that of the V_(H) of HL1 and HL2 (precursor or mature form; SEQ ID NO:1 and SEQ ID NO:3, respectively) and a V_(L) chain that has an amino acid sequence at least 85% (e.g., 90%, 92%, 94%, 95%, 96%, 97%, 98%, or 99%) identical to that of the V_(L) of HL2 (precursor or mature form; SEQ ID NO:5 and SEQ ID NO:7, respectively). These variants are capable of binding to an IL-20 molecule, particularly a human IL-20 molecule. In some examples, the variants possess similar antigen-binding affinity relative to the exemplary humanized antibody described above (e.g., having a K_(d)<4×10⁻⁹).

The “percent identity” of two amino acid sequences is determined using the algorithm of Karlin and Altschul Proc. Natl. Acad. Sci. USA 87:2264-68, 1990, modified as in Karlin and Altschul Proc. Natl. Acad. Sci. USA 90:5873-77, 1993. Such an algorithm is incorporated into the NBLAST and XBLAST programs (version 2.0) of Altschul, et al. J. Mol. Biol. 215:403-10, 1990. BLAST protein searches can be performed with the XBLAST program, score=50, wordlength=3 to obtain amino acid sequences homologous to the protein molecules of interest. Where gaps exist between two sequences, Gapped BLAST can be utilized as described in Altschul et al., Nucleic Acids Res. 25(17):3389-3402, 1997. When utilizing BLAST and Gapped BLAST programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used.

In some embodiments, the functional variants described above contains one or more mutations (e.g., conservative substitutions) in the FRs of either the V_(H) or the V_(L) as compared to those in SEQ ID NO:3 or SEQ ID NO:7. Preferably, such mutations do not occur at residues which are predicted to interact with one or more of the CDRs (see Example 1 below). As known in the art, mutations within the FR regions are unlikely to affect the antigen-binding activity of the antibody. In other embodiments, the functional variants described herein contain one or more mutations (e.g., 1, 2, or 3) within one or more of the CDR regions. Preferably, such functional variants retain the same regions/residues responsible for antigen-binding as the parent, such as the same specificity-determining residues inside the CDRs.

Any of the humanized anti-IL-20 antibodies can be prepared via conventional methodology, e.g., recombination technology. See, e.g., Green et al. (1994) Nature Genetics 7, 13; and U.S. Pat. Nos. 5,545,806 and 5,569,825.

When a full-length antibody is desired, coding sequences of any of the humanized V_(H) and V_(L) chains described herein can be linked to the coding sequences of the Fc region of a human immunoglobulin and the resultant gene encoding a full-length antibody heavy and light chains can be expressed and assembled in a suitable host cell, e.g., a plant cell, a mammalian cell, a yeast cell, or an insect cell.

Antigen-binding fragments can be prepared via routine methods. For example, F(ab′)₂ fragments can be produced by pepsin digestion of an full-length antibody molecule, and Fab fragments that can be generated by reducing the disulfide bridges of F(ab′)₂ fragments. Alternatively, such fragments can be prepared via recombinant technology by expressing the heavy and light chain fragments in suitable host cells (e.g., E. coli, yeast, mammalian, plant, or insect cells) and have them assembled to form the desired antigen-binding fragments either in vivo or in vitro.

A single-chain antibody can be prepared via recombinant technology by linking a nucleotide sequence coding for a heavy chain variable region and a nucleotide sequence coding for a light chain variable region. Preferably, a flexible linker is incorporated between the two variable regions.

A humanized anti-IL-20 antibody produced as described above can be examined to determine their properties, such as antigen-binding activity and biological function, following routine methods, e.g., those described in Example 2 below.

Also disclosed herein are nucleic acids encoding any of the humanized anti-IL-20 antibodies described herein, vectors such as expression vectors comprising these nucleic acids, and host cells comprising the vectors. In one example, both the heavy and light chain coding sequences are included in one expression vector. In another example, each of the heavy and light chains of the antibody is cloned in to an individual vector. In the latter case, the expression vectors encoding the heavy and light chains can be co-transfected into one host cell for expression of both chains, which can be assembled to form intact antibodies either in vivo or in vitro. Alternatively, the expression vector encoding the heavy chain and that encoding the light chain can be introduced into different host cells for expression each of the heavy and light chains, which can then be purified and assembled to form intact antibodies in vitro.

Uses of Humanized Anti-IL-20 Antibody

The humanized anti-IL-20 antibodies described herein can be used as therapeutic agents and diagnostic agents, as well as research tools in biochemistry, molecular biology, and medical researches.

Accordingly, disclosed herein are methods for treating a disease associated with the IL-20-mediated cell signaling (e.g., an inflammatory disease such as rheumatoid arthritis, osteoporosis, cancer, stroke, and renal failure) comprising administering to a subject in need of the treatment an effective amount of any of the humanized anti-IL-20 antibody described herein.

The humanized anti-IL-20 antibodies described herein can be used for treating diseases associated with an IL-20-mediated signaling pathway, such as an inflammatory disease (e.g., rheumatoid arthritis), stroke, osteoporosis, and cancer (e.g., breast cancer, prostate cancer, colon cancer, lung cancer, renal cell carcinoma, giant cell tumor of bone, oral cancer, esophagus cancer, or multiple myeloma).

In some embodiments, the method described herein aims at treating osteoporosis and alleviating bone loss. A human subject who needs this treatment can be a patient suffering from or is suspected of having osteoporosis, which is a disease characterized by low bone mass and loss of bone tissue, resulting in weak and fragile bones. Osteoporosis to be treated by the method described herein can be induced by various factors, e.g., low levels of estrogen (e.g., caused by menopause), inadequate up take of calcium and vitamin D, inflammation (e.g., rheumatoid arthritis), cancer-induced osteolysis, and low levels of androgen (e.g., caused by andropause).

In one example, a subject (e.g., a human patient) who needs the just-noted treatment is a post-menopausal woman or a post-andropausal man. In another example, the patient is a rheumatoid arthritis patient who suppers from or is suspected of having bone erosion. In yet another example, the patient suffers from or is suspected of having osteolysis induced by cancer, such as breast cancer, prostate cancer, liver cancer, colon cancer, multiple myeloma, or lung cancer.

As used herein, the term “treating” refers to the application or administration of a composition including one or more active agents to a subject, who has a disorder/disease associated with the signaling pathway mediated by IL-20 (e.g., those described herein), a symptom of the disease/disorder, or a predisposition toward the disease/disorder, with the purpose to cure, heal, alleviate, relieve, alter, remedy, ameliorate, improve, or affect the disease/disorder, the symptom of the disease/disorder, or the predisposition toward the disease/disorder.

“An effective amount” as used herein refers to the amount of each active agent required to confer therapeutic effect on the subject, either alone or in combination with one or more other active agents. Effective amounts vary, as recognized by those skilled in the art, depending on the particular condition being treated, the severity of the condition, the individual patient parameters including age, physical condition, size, gender and weight, the duration of the treatment, the nature of concurrent therapy (if any), the specific route of administration and like factors within the knowledge and expertise of the health practitioner. These factors are well known to those of ordinary skill in the art and can be addressed with no more than routine experimentation. It is generally preferred that a maximum dose of the individual components or combinations thereof be used, that is, the highest safe dose according to sound medical judgment. It will be understood by those of ordinary skill in the art, however, that a patient may insist upon a lower dose or tolerable dose for medical reasons, psychological reasons or for virtually any other reasons.

In some embodiments, the amount of the humanized anti-IL-20 antibody described herein is effective in suppressing inflammation (e.g., reducing the level of inflammation by at least 20%, 30%, 50%, 80%, 100%, 200%, 400%, or 500% as compared to a blank control). In other embodiments, the amount of the humanized anti-IL-20 antibody described herein is effective in inhibiting bone loss (e.g., reducing the level of bone loss by at least 20%, 30%, 50%, 80%, 100%, 200%, 400%, or 500% as compared to a blank control).

To practice a treatment disclosed herein, any of the humanized anti-IL-20 antibody or the encoding nucleic acid can be mixed with a pharmaceutically acceptable carrier to form a pharmaceutical composition for administration to a subject in need of the treatment. A pharmaceutically acceptable carrier is compatible with the active ingredient(s) in the composition (and preferably, capable of stabilizing it) and not deleterious to the subject to be treated. For example, solubilizing agents such as cyclodextrins, which form more soluble complexes with a humanized anti-IL-20 antibody as described herein, or a nucleic acid encoding such, or more solubilizing agents, can be utilized as pharmaceutical carriers for delivery of the agonist/antagonist. Examples of other carriers include colloidal silicon dioxide, magnesium stearate, sodium lauryl sulfate, and D&C Yellow #10. See, e.g., Remington's Pharmaceutical Sciences, Edition 16, Mack Publishing Co., Easton, Pa. (1980); and Goodman and Gilman's “The Pharmacological Basis of Therapeutics”, Tenth Edition, Gilman, J. Hardman and L. Limbird, eds., McGraw-Hill Press, 155-173, 2001.

The pharmaceutical compositions, formulated for therapeutic uses, may be prepared for storage by mixing an agent having the desired degree of purity with optional pharmaceutically acceptable carriers, excipients or stabilizers (Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980)), in the form of lyophilized formulations or aqueous solutions. Acceptable carriers, excipients, or stabilizers are nontoxic to recipients at the dosages and concentrations employed, and include buffers such as phosphate, citrate, and other organic acids; antioxidants including ascorbic acid and methionine; preservatives (such as octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight (less than about 10 residues) polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugars such as sucrose, mannitol, trehalose or sorbitol; salt-forming counter-ions such as sodium; metal complexes (e.g., Zn-protein complexes); and/or non-ionic surfactants such as TWEEN™, PLURONICS™ or polyethylene glycol (PEG).

To treating a target disease, an effective amount of the pharmaceutical composition noted above can be administered to a subject (e.g., a human) in need of the treatment via a suitable route. A human subject who needs the treatment may be a human patient having, at risk for, or suspected of having a disorder associated with the signaling pathway mediated by IL-20. Such a patient can be identified by routine medical examination.

If necessary, the pharmaceutical composition described herein, containing a humanized anti-IL-20 antibody or its encoding nucleic acid(s), can be co-administered with a second therapeutic agent. The selection of the second therapeutic agent depends on the type of the disease to be treated. For example, if the target disease is an inflammatory disease such as rheumatoid arthritis, the second agent can be a TNFα antagonist, which can be an etanercept polypeptide, infliximab, or adalimumab. In another example, if the target disease is a cancer, the second agent can be an anti-cancer agent (e.g., Tamoxifen, Taxol, Erlotinib, Dexasone, and Herceptin).

When the pharmaceutical composition described here is co-used with a second therapeutic agent, a sub-therapeutic dosage of either the composition or of the second agent, or a sub-therapeutic dosage of both, can be used in the treatment of a subject having, or at risk of developing a disease or disorder associated with the cell signaling mediated by IL-20. A “sub-therapeutic dose” as used herein refers to a dosage, which is less than that dosage which would produce a therapeutic result in the subject if administered in the absence of the other agent or agents. Thus, the sub-therapeutic dose of an agent is one which would not produce the desired therapeutic result in the subject in the absence of the administration of the agents of the invention. Therapeutic doses of many agents that are in clinical use are well known in the field of medicine, and additional therapeutic doses can be determined by those of skill without undue experimentation. Therapeutic dosages have been extensively described in references such as Remington's Pharmaceutical Sciences, 18th ed., 1990; as well as many other medical references relied upon by the medical profession as guidance for the treatment of diseases and disorders.

Conventional methods, known to those of ordinary skill in the art of medicine, can be used to administer the pharmaceutical composition to the subject, depending upon the type of diseases to be treated or the site of the disease. This composition can also be administered via other conventional routes, e.g., administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir. The term “parenteral” as used herein includes subcutaneous, intracutaneous, intravenous, intramuscular, intraarticular, intraarterial, intrasynovial, intrasternal, intrathecal, intralesional, and intracranial injection or infusion techniques. In addition, it can be administered to the subject via injectable depot routes of administration such as using 1-, 3-, or 6-month depot injectable or biodegradable materials and methods.

Injectable compositions may contain various carriers such as vegetable oils, dimethylactamide, dimethyformamide, ethyl lactate, ethyl carbonate, isopropyl myristate, ethanol, and polyols (glycerol, propylene glycol, liquid polyethylene glycol, and the like). For intravenous injection, water soluble antibodies can be administered by the drip method, whereby a pharmaceutical formulation containing the antibody and a physiologically acceptable excipients is infused. Physiologically acceptable excipients may include, for example, 5% dextrose, 0.9% saline, Ringer's solution or other suitable excipients. Intramuscular preparations, e.g., a sterile formulation of a suitable soluble salt form of the antibody, can be dissolved and administered in a pharmaceutical excipient such as Water-for-Injection, 0.9% saline, or 5% glucose solution.

When a nucleic acid(s) encoding a humanized anti-IL-20 antibody as described herein is used as the therapeutic agent, the nucleic acid(s) or a vector(s) expressing the antibody can be delivered to a subject by methods, such as that described in Akhtar et al., 1992, Trends Cell Bio. 2, 139. For example, it can be introduced into cells using liposomes, hydrogels, cyclodextrins, biodegradable nanocapsules, or bioadhesive microspheres. Alternatively, the nucleic acid or vector can be locally delivered by direct injection or by use of an infusion pump. Other approaches include employing various transport and carrier systems, for example through the use of conjugates and biodegradable polymers.

To facilitate delivery, any of the humanized anti-IL-20 antibody or its encoding nucleic acids can be conjugated with a chaperon agent. As used herein, “conjugated” means two entities are associated, preferably with sufficient affinity that the therapeutic benefit of the association between the two entities is realized. Conjugated includes covalent or noncovalent bonding as well as other forms of association, such as entrapment of one entity on or within the other, or of either or both entities on or within a third entity (e.g., a micelle).

The chaperon agent can be a naturally occurring substance, such as a protein (e.g., human serum albumin, low-density lipoprotein, or globulin), carbohydrate (e.g., a dextran, pullulan, chitin, chitosan, inulin, cyclodextrin or hyaluronic acid), or lipid. It can also be a recombinant or synthetic molecule, such as a synthetic polymer, e.g., a synthetic polyamino acid. Examples of polyamino acids include polylysine (PLL), poly L-aspartic acid, poly L-glutamic acid, styrene-maleic acid anhydride copolymer, poly(L-lactide-co-glycolied) copolymer, divinyl ether-maleic anhydride copolymer, N-(2-hydroxypropyl)methacrylamide copolymer (HMPA), polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyurethane, poly(2-ethylacryllic acid), N-isopropylacrylamide polymers, and polyphosphazine.

In one example, the chaperon agent is a micelle, liposome, nanoparticle, or microsphere, in which the oligonucleotide/interfering RNA is encapsulated. Methods for preparing such a micelle, liposome, nanoparticle, or microsphere are well known in the art. See, e.g., U.S. Pat. Nos. 5,108,921; 5,354,844; 5,416,016; and 5,527,528.

In another example, the chaperon agent serves as a substrate for attachment of one or more of a fusogenic or condensing agent.

A fusogenic agent is responsive to the local pH. For instance, upon encountering the pH within an endosome, it can cause a physical change in its immediate environment, e.g., a change in osmotic properties which disrupts or increases the permeability of the endosome membrane, thereby facilitating release of the antisense oligonucleotide into host cell's cytoplasm. A preferred fusogenic agent changes charge, e.g., becomes protonated at a pH lower than a physiological range (e.g., at pH 4.5-6.5). Fusogenic agents can be molecules containing an amino group capable of undergoing a change of charge (e.g., protonation) when exposed to a specific pH range. Such fusogenic agents include polymers having polyamino chains (e.g., polyethyleneimine) and membrane disruptive agents (e.g., mellittin). Other examples include polyhistidine, polyimidazole, polypyridine, polypropyleneimine, and a polyacetal substance (e.g., a cationic polyacetal).

A condensing agent interacts with the antisense oligonucleotide, causing it to condense (e.g., reduce the size of the oligonucleotide), thus protecting it against degradation. Preferably, the condensing agent includes a moiety (e.g., a charged moiety) that interacts with the oligonucleotide via, e.g., ionic interactions. Examples of condensing agents include polylysine, spermine, spermidine, polyamine or quarternary salt thereof, pseudopeptide-polyamine, peptidomimetic polyamine, dendrimer polyamine, arginine, amidine, protamine, cationic lipid, cationic porphyrin, and alpha helical peptide.

Without further elaboration, it is believed that one skilled in the art can, based on the above description, utilize the present invention to its fullest extent. The following specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. All publications cited herein are incorporated by reference for the purposes or subject matter referenced herein.

Example 1 Preparation of Humanized Anti-IL-20 Antibodies

Exemplary humanized anti-IL-20 antibodies HL1 and HL2 were prepared as follows, using mouse monoclonal antibody 7E (mAb 7E) as the parent antibody. mAb 7E was described in U.S. Pat. Nos. 7,435,800 and 7,786,274, both of which are incorporated by reference herein. The amino acid sequences of the V_(H) and V_(L) chains of mAb 7E are shown below:

Amino Acid Sequence of mAb 7E V_(H):

M Y L G L N Y V F I V F L L N G V Q S E L K L E E S G G G L V Q P G G S M K L S C A A S G F T F S D A W M D W V R Q S P E K G L E W I A E I R S K A N N Y A T Y F A E S V K G R F T I S R D D S K S G V Y L Q M N N L R A E D T G I Y F C T K L S L R Y W F F D V W G A G T T V T V S S (SEQ ID NO:9) Amino Acid Sequence of mAb 7E V_(L): M M S P A Q F L F L L V L W I R E T N G D F V M T Q T P L T L S V T I G Q P A S I S C K S S Q S L L D S D G K T Y L N W L L Q R P G Q S P K H L I Y L V S K L D S G V P D R F T G S G S G T D F T L R I S R V E A E D L G V Y Y C W Q S T H F P W T F G G G T K L E I K (SEQ ID NO:10) The italic regions refer to the signal peptides in 7E V_(H) and V_(L). Humanization of 7E V_(H)

Human V_(H) sequences having framework regions (FRs) homologous to those of the mAb 7E V_(H) chain were identified by searching the GenBank database using FRs of 7E V_(H) as search queries. A sequence alignment between 7E V_(H) and its predicted parental germline V_(H) segment J606.4.82 (Johnston et al. 2006, J. Immunol. 176:4221-4234) is shown below:

          1          2          3 123456789 0123456789 0123456789 0123456789 7E VH ELKLEESGG GLVQPGGSMK LSCAASGFTF SDAWMDWVRQ J606.4.82 EVKLEESGG GLVQPGGSMK LSCAASGFTF SDAWMDWVRQ  * 4          5             6          7 0123456789 0122223456789 0123456789 0123456789               abc 7E VH SPEKGLEWIA EIRSKANNYATYF AESVKGRFTI SRDDSKSGVY J606.4.82 SPEKGLEWVA EIRNKANNHATYY AESVKGRFTI SRDDSKSSVY         *     *    *   *                   *                          1            1 8             9          0            1 0122223456789 0123456789 000123456789 0123    abc                    ab 7E VH LQMNNLRAEDTGI YFCTKLSLRY WFFDVWGAGTTV TVSS (SEQ ID NO: 11) J606.4.82 LQMNSLRAEDTGI YYCTR (SEQ ID NO: 12)     *          *  *

Positions of the residues indicated above were determined according to Kabat et al., 1991, “Sequences of Proteins of Immunological Interests,” Fifth edition, NIH Publication No. 91-3242, U.S. Department of Health and Human Services. The CDR regions are underlined and numbered following Kabat et al. Asterisks indicate the differences between the 7E V_(H) and the human parental germline V_(H).

Human L06102 V_(H) chain (Shaw et al. 1995, Ann. N.Y. Acad. Sci. 764:370-373) was chosen as an acceptor for humanization of the heavy chain. The CDR sequences of 7E V_(H) were first transferred to the corresponding positions of L06102 V_(H). Next, residues within the FRs of 7E V_(H) at positions 48, 49, and 94 were retained in the humanized V_(H). These residues were predicted to interact with the CDRs as determined by three-dimensional modeling analysis. The amino acid sequence of the resultant humanized V_(H), Hu7E V_(H), aligned with the sequences of 7E V_(H) and L06102 V_(H), is shown in below:

          1          2          3 123456789 0123456789 0123456789 0123456789 7E VH ELKLEESGG GLVQPGGSMK LSCAASGFTF SDAWMDWVRQ Hu7E VH EVQLVESGG GLVQPGGSLK LSCAASGFTF SDAWMDWVRQ L06102 VH EVQLVESGG GLVQPGGSLK LSCAASGFTF S-----WVRQ 4          5             6          7 0123456789 0122223456789 0123456789 0123456789               abc 7E VH SPEKGLEWIA EIRSKANNYATYF AESVKGRFTI SRDDSKSGVY Hu7E VH ASGKGLEWIA EIRSKANNYATYF AESVKGRFTI SRDDSKNTAY L06102 VH ASGKGLEWVG ------------- ------RFTI SRDDSKNTAY                          1            1 8             9          0            1 0122223456789 0123456789 000123456789 0123    abc                    ab 7E VH LQMNNLRAEDTGI YFCTKLSLRY WFFDVWGAGTTV TVSS (SEQ ID NO: 11) Hu7E VH LQMNSLKTEDTAV YYCTKLSLRY WFFDVWGQGTLV TVSS (SEQ ID NO: 3) L06102 VH LQMNSLKTEDTAV YYCTG----- -----WGQGTLV TVSS (SEQ ID NO: 13)

Again, positions of the residues in the V_(H) chain are determined following Kabat et al. and the CDR regions are underlined. The CDRs in the L06102 V_(H), which were replaced with those of the 7E V_(H), are not shown in the alignment above. The FR residues noted above are also underlined.

Humanization of 7E V_(L)

Shown below is a sequence alignment between mAb 7E V_(L) and its predicted parental germline V segment, bd2 (Schable et al. 1999, Eur. J. Immunol. 29: 2082-2086). Positions of the residues are determined following Kabat et al. The asterisks indicate differences between 7E V_(L) and bd2 amino acid sequences.

          1          2               3 123456789 0123456789 012345677777789 0123456789                              abcde 7E VL DFVMTQTPL TLSVTIGQPA SISCKSSQSLLDSDG KTYLNWLLQR bd2 DVVMTQTPL TLSVTIGQPA SISCKSSQSLLDSDG KTYLNWLLQR  * 4          5          6          7 0123456789 0123456789 0123456789 0123456789 7E VL PGQSPKHLIY LVSKLDSGVP DRFTGSGSGT DFTLRISRVE bd2 PGQSPKRLIY LVSKLDSGVP DRFTGSGSGT DFTLKISRVE       *                              *                       1 8          9          0 0123456789 0123456789 01234567 7E VL AEDLGVYYCW QSTHFPWTFG GGTKLEIK (SEQ ID NO: 14) bd2 AEDLGVYYCW QGTHFP (SEQ ID NO: 16)             *

Based on the homology search using the 7E V_(L) framework sequences as search queries, a human Vκ chain described in GenBank Accession Number BG758592 was chosen as an acceptor for humanization of the V_(L) chain.

The CDR sequences of 7E V_(L) were transferred to the corresponding positions of the BG758592 V_(L) chain. Further, positions 2, 36 and 46 in the framework regions of 7E V_(L) were retained in the humanized V_(L). These positions were predicted to interact with CDRs as determined by the three-dimensional modeling analysis disclosed above. The amino acid sequence of the resultant humanized V_(L), Hu7E V_(L)1, aligned with those of the 7E V_(L) and BG758592 V_(L), is shown below:

          1          2               3 123456789 0123456789 012345677777789 0123456789                              abcde 7E VL DFVMTQTPL TLSVTIGQPA SISCKSSQSLLDSDG KTYLNWLLQR Hu7E VL1 DFVMTQTPL SLSVTPGQPA SISCKSSQSLLDSDG KTYLNWLLQK Hu7E VL2 DIVMTQTPL SLSVTPGQPA SISCKSSQSLLDSDG KTYLNWLLQK BG758592 VL DIVMTQTPL SLSVTPGQPA SISC----------- -----WYLQK 4          5          6          7 0123456789 0123456789 0123456789 0123456789 7E VL PGQSPKHLIY LVSKLDSGVP DRFTGSGSGT DFTLRISRVE Hu7E VL1 PGQSPQHLIY LVSKLDSGVP DRFSGSGSGT DFTLKISRVE Hu7E VL2 PGQSPQHLIY LVSKLDSGVP DRFSGSGSGT DFTLKISRVE BG758592 VL PGQSPQLLIY -------GVP DRFSGSGSGT DFTLKISRVE                       1 8          9          0 0123456789 0123456789 01234567 7E VL AEDLGVYYCW QSTHFPWTFG GGTKLEIK (SEQ ID NO: 14) Hu7E VL1 AEDVGVYYCW QSTHFPWTFG GGTKVEIK (SEQ ID NO: 15) Hu7E VL2 AEDVGVYYCW QSTHFPWTFG GGTKVEIK (SEQ ID NO: 7) BG758592 VL AEDVGVYYC- --------FG GGTKVEIK (SEQ ID NO: 17)

Numbers above the sequences indicate amino acid residue positions in VL as determined following Kabat et al. The CDR sequences and the residues within the FRs noted above are underlined in the 7E V_(L). The CDR regions in BG758592 V_(L) are omitted.

While a phenylalanine residue (F) at position 2 in mouse 7E V_(L) is located at a framework position that was predicted to be important for the formation of the proper CDR structures, detailed molecular modeling analysis of the 7E variable regions suggested that an amino acid residue at position 2 in Hu7E VL1 could be replaced with the corresponding residue, isoleucine (I), in the human BG758592 V_(L) without losing the antigen-binding affinity. In order to further reduce potential immunogenicity of humanized 7E antibody, a second humanized V_(L) (Hu7E V_(L)2) was designed, in which a phenylalanine residue at position 2 in Hu7E V_(L)1 was replaced with an isoleucine residue. The amino acid sequence of Hu7E V_(L)2 is also shown in the alignment above.

Nucleotide sequences encoding the humanized Hu7E V_(H) and Hu7E V_(L)1 and V_(L)2 were each cloned into an expression vector from Invivogen via the EcoRI and NheI cloning sites (for the V_(H) gene) or the NcoI and BsiWI cloning sites (for the V_(L)1 and V_(L)2 genes). The resultant expression vectors were co-transfected into CHO cells following routine methods. The transfected CHO cells were cultured under suitable conditions allowing the expression of the Hu7E V_(H) and Hu7E V_(L)1 chains (form humanized antibody HL1) or Hu7E V_(H) and V_(L)2 chains (form humanized antibody HL2). The culture medium was then collected and the humanized anti-IL-20 antibodies contained therein were isolated by a protein A column.

Example 2 Biological Function Analysis of Humanized Anti-IL-20 Antibody

The antigen binding affinity of the humanized anti-IL-20 antibodies prepared in Example 1 above, as well as those of the parent antibody and a chimeric antibody derived therefrom, was examined via the standard BIOCORE technology following the manufacturer's protocol. The results are shown below:

Parent antibody 7E:  6.8 × 10⁻¹⁰ Humanized antibody HL1: 3.6 × 10⁻⁹ Humanized antibody HL2: 1.2 × 10⁻⁹ Chimeric antibody: 4.2 × 10⁻⁹

Unexpected, both humanized antibodies HL1 and HL2 showed antigen-binding affinities similar to that of the parent antibody. In particular, humanized antibody HL2 showed an antigen-binding affinity higher than the chimeric antibody.

The biological function of the humanized anti-IL-20 antibody noted above was analyzed via an inhibition of osteoclast differentiation assay. The parent mouse 7E antibody and a chimeric antibody derived therefrom were used as controls. The chimeric antibody was constructed by ligating the mAb 7E variable regions with the Fc region of a human IgG.

The osteoclast differentiation assay was performed as described in Hsu et al., J Exp Med. 2011, 208(9):1849-61. Briefly, bone marrow cells (BMCs) from the tibias of C57BL6 mice were incubated for 12 h (37° C./5% CO₂). Non-adherent cells were collected and seeded in 24-well plates (2×10⁶ cells per well) and cultured in the same medium supplemented with 30 ng/ml of recombinant murine macrophage colony-stimulating factor (M-CSF) (PeproTech). After 48 hours, M-CSF-derived osteoclast precursor cells were cultured with murine M-CSF (40 ng/ml) and sRANKL (100 ng/ml) (PeproTech) until the end of the experiment.

To analyze the effect of the 7E, chimeric, and humanized antibodies on osteoclast differentiation, BMCs were cultured for 12 h. Non-adherent cells were cultured in a-MEM containing MCSF to drive to OC precursors for 48 hours. One of the three anti-IL-20 antibodies, the 7E antibody, chimeric antibody, and humanized antibody (0.5 μg/ml) or a control hIgG (0.5 μg/ml) was added to the OC precursors. The cells were incubated with M-CSF (40 ng/ml) and sRANKL (100 ng/ml) for 6-8 days. To calculate the number of osteoclasts, the cells were fixed in acetone and stained for TRAP using an acid phosphatase kit (Sigma-Aldrich). TRAP-positive multinucleated cells containing three or more nuclei were considered as osteoclasts. As shown in the FIG. 1, the humanized antibody Hu HL2 (7E HL-2) unexpectedly exhibited the same effect as the parent mAb 7E in inhibiting OC differentiation. The humanized antibody inhibited 50% of OC differentiation at the concentration of 0.5 ug/ml. These results demonstrate that, like the parent mouse antibody, the humanized anti-IL-20 antibody can be used as a therapeutic agent in alleviating bone loss, e.g., bone loss associated with post-menopause osteoporosis, rheumatoid arthritis, cancer-induced osteolysis.

Other Embodiments

All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.

From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Thus, other embodiments are also within the claims. 

What is claimed is:
 1. An isolated humanized antibody, comprising: a heavy chain variable region (V_(H)), which comprises an amino acid sequence that is (i) identical to SEQ ID NO:1 or SEQ ID NO:3, or (ii) at least 90% identical to SEQ ID NO:1 or SEQ ID NO:3, and consisting of one or more mutations in one or more framework regions (FRs) in SEQ ID NO:1 or SEQ ID NO:3, and a light chain variable region (V_(L)), which comprises an amino acid sequence that is (i) identical to SEQ ID NO:5 or SEQ ID NO:7, or (ii) at least 90% identical to SEQ ID NO:5 or SEQ ID NO:7, and consisting of one or more mutations in one or more FRs in SEQ ID NO:5 or SEQ ID NO:7; wherein the antibody binds to human interleukin 20 (IL-20).
 2. The isolated antibody of claim 1, wherein the V_(H) comprises an amino acid sequence at least 95% identical to SEQ ID NO:1 or SEQ ID NO:3, and the V_(L) comprises an amino acid sequence at least 95% identical to SEQ ID NO:5 or SEQ ID NO:7.
 3. The isolated antibody of claim 2, wherein the V_(H) comprises the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:3, and the V_(L) comprises the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:7.
 4. The isolated antibody of claim 1, wherein the antibody is a full-length antibody.
 5. The isolated antibody of claim 4, wherein the full-length antibody is an IgG molecule.
 6. The isolated antibody of claim 1, wherein the antibody is an antigen-binding fragment.
 7. The isolate antibody of claim 6, wherein the antigen-binding fragment is Fab.
 8. A pharmaceutical composition, comprising the isolated antibody of claim 1 and a pharmaceutically acceptable carrier.
 9. A method for treating a disease associated with an upregulated IL-20-mediated signaling pathway, comprising administering to a patient in need thereof an effective amount of the antibody of claim
 1. 10. The method of claim 9, wherein the disease associated with the IL-20-mediated signaling pathway is osteoporosis or rheumatoid arthritis.
 11. The method of claim 10, wherein the disease associated with the IL-20-mediated signaling pathway is osteoporosis.
 12. The method of claim 11, wherein the osteoporosis is caused by an inflammatory disease, estrogen deficiency, androgen deficiency, or cancer-induced osteolysis.
 13. The isolated antibody of claim 1, wherein the one or more mutations in both the V_(H) and V_(L) are conservative substitutions.
 14. The isolated antibody of claim 1, wherein the V_(H) retains the amino acid residues at positions 48, 49, and 94 in SEQ ID NO:3 and the V_(L) retains the amino acid residues at positions 2, 36, and 46 in SEQ ID NO:7.
 15. The isolated antibody of claim 1, wherein the V_(H) comprises the amino acid sequence of SEQ ID NO:1 or SEQ ID NO:3, and the V_(L) comprises the amino acid sequence of SEQ ID NO:15. 